Wednesday, 28 February 2007

Resin Casting Tutorial: Part II

Once 24 hours have passed, it is time to put the mold upside down and remove its bottom.

This is how it looks. Now I remove the excess of silicone (you can save it for later recycling) and the casting frame.

Now it looks cleaner.

I remove the plastecine used to mask the parts we did not want to include in this half (Don't use for this anything with a cutting edge or you could damage the mold).

I clean any plasticine rests with rubbing alcohol and a tissue.

Now I put the piece back to the mold and rebuild the casting frame.

I add a demolding agent to the silicone. This is to avoid that the silicone that I am about to pour reacts to the first mold half, forming a solid block with you model in the middle!.

I use 5% vaseline disolved in 95% white spirit, so I let it dry before pouring the rest of the silicone. You can also put a little blob of vaseline, heat it with a hairdrier and spread it with a brush (pay attention to not damage your model with the heat). In any case, you don't need to apply vaseline to the model, just to the mold, as it can obscure detail.

The rest goes exactly as in the other half. "Paint" the silicone.

And pour the rest.

Now we must wait for further 24 hours to let the mold cure.

In the meantime, we'll learn how to do a vibrating tray to avoid bubbles during resin casting.